There is always a lingering doubt in everyone’s
mind, as to what Grid is exactly, and how it differs from other well
known architectures such as Cluster and P2P architectures. In this
chapter, we will highlight the true nature of Grid and Clustering
architectures. We will also look at other buzzwords such as
‘on-demand’ and ‘utility’ computing.

There is a somewhat hazy notion and
understanding of Grid and the types of Grids among many IT
technologists. Sometimes they do not find a clear demarcation
between grids and other related technologies like clusters. We will
examine the differences between the Clusters and Grid.

“Oops … Am I in Grid now?”

Another thing that often needs explanation is
the concept of On-Demand and Utility Computing Model, which is often
termed as Grid Computing.

The Clustering of Servers has been with us for
about two decades and it is one of the most widely understood, being
deployed in scientific, research and commercial worlds. We are well
versed with the concept of aggregating the servers, and view them as
the single system image (SSI). Now, with the gradual adoption of
grid technologies, one often wonders if grid works with clusters or
if it replaces the clustering. How does grid change the whole
perspective of the sharing of the servers?